Measuring advanced permanent magnets with free form

L. Van Bockstal, S. Vandenborn and J. Deschagt

The open loop hysteresis meter allows for the measurement of permanent magnetic material without the need for pole shoes.  Using strong pulsed magnetic fields allows to measure the full hysteresis curve of the highest coercive material available nowadays. As such, the open loop hysteresis meter is well suited for measuring state-of-the-art permanent magnet material

 

The use of the open loop hysteresis meter recently gained more interest due to advances in measurement sensors and measuring techniques. For this instrument, we developed a magnetic moment sensor consisting of a set of pick-up coils for measuring the magnetic moment for arbitrary shaped and positioned samples including the compensation of the background signal of the axial field coil (patent pending).

 

In order to demonstrate the possibilities and limitations of the instrument, an analysis is presented of the measurement quality. With the present status, the instrument shows to be adequate in measuring the hysteresis loops of a wide range of geometries with a precision of < 1%.